1. Field of the Invention
This invention relates to a process for recovering rhodium from a still heel from the hydroformylation of olefins. More specifically, this invention relates to a process for recovering rhodium from a still heel from the hydroformylation of olefins in the presence of triaryl phosphite ligands and a rhodium complex catalyst.
2. Prior Art
Rhodium metal is known in the art as a catalyst in hydroformylation reactions. In such reactions the rhodium may be complexed with various ligands to render it catalytically active. In U.S. Pat. No. 3,998,622 there is disclosed a method for preparing a novel rhodium metal form from a still heel from the hydroformylation of olefins where the ligand in the catalyst complex is a trialkyl phosphorus compound. However, the process of U.S. Pat. No. 3,998,622 with a triaryl phosphorus ligand does not result in the recovery of at least 90% of the rhodium nor does it produce a rhodium that can be readily dissolved in a triaryl phosphite ligand catalyst solution.
U.S. Pat. No. 3,547,964 discloses the recovery of Group VIII metal complexes by a process comprising treating a nonpolar solvent containing tars and high boiling hydroformylation products with a sufficient amount of a peroxide to precipitate the Group VIII metal complex and separating and recovering said precipitate therefrom. This invention is limited, however, to triaryl phosphine ligands.